refactor: Phase 5 — Migrate layout shell to SUMI tokens
- Sidebar: bg-raised, border-faint tokens
- Header: glass bg + backdrop-blur-12px, z-200 sticky, SUMI durations
- PlayerBarGlass: glass-bg + blur-16px, accent colors, remove glow
- PlayerBarProgress: solid accent fill, SUMI border tokens
- PlayerBarRight/TrackInfo: text-foreground, SUMI border tokens
- MiniPlayer: glass-bg, border-faint, z-200, SUMI shadows
- GlobalPlayer: SUMI z-index and duration tokens
- DashboardLayout: SUMI z-raised, duration tokens
Co-authored-by: Cursor <cursoragent@cursor.com>